Fuel Cost Calculator (Trip Cost)
Work out how much fuel a road trip needs and what it costs — in miles or km, with MPG (US or UK), L/100km or km/L — split between passengers.
How to use
- 1Enter the distance, your car's fuel economy and the fuel price.
- 2Tick round trip and add passengers to split the cost.
How it's calculated
Fuel = distance × litres per km (converted from your economy unit). Cost = fuel × price. US gallon = 3.785 L; UK gallon = 4.546 L.
Frequently asked questions
Why are UK and US MPG different?
A UK (imperial) gallon is about 20% bigger than a US gallon, so the same car shows a higher MPG figure in the UK.
Is the official fuel economy realistic?
Real-world consumption is often 10–20% worse than official figures, especially with motorway speeds, air conditioning or a loaded car.
Does this include tolls and parking?
No — only fuel. Add tolls, parking and wear if you're splitting the full cost of a trip.